Forking angles!

[davepl]

So I'm trying to figure out whether my LS swap is going to mate up correctly between the engine, trans, and clutch.

Centerforce has a very complicated approach that measures dimensions from the flywheel flange and the trans face, but since an LS motor has a different flange depth and flywheel thickness it's not easy to apply to my situation. At the end they show a picture of the fork and that it should have an acute angle. So the angle seems to override the measurements.

Hurst's site skips the measurements and just cares about the angle, like the picture below.

I have verified that my bellhousing face to flywheel surface is the same (within 0.02") between the LS and the big block, so I think that's the most important.

But am I safe to rely on the clutch fork angle as an indication that it's set up properly? I have an adjustable ball stud to make it right if its not.

[special-K]

I keep seeing these LS related threads by you here. Have you decided to go that route in your C3500 or do you have another truck I don't know about? Not long ago you made it clear the 402 was staying. Am I wrong?

[davepl]

It's not my blue truck, it's a blue... car. I'm replacing a ZZ502 BBC with an LS3 eRod. But I prefer these forums over the Camaro forums so as long as the question is completely general to the LS motor, I ask here. If it's got anything to do with the car side, I ask there. Hope nobody minds so long as it's powertrain-only stuff.

So the big blue truck stays a factory big block. In fact this is the first time in my life I've ever replaced a big block with a small block, and heaven knows I've gone the other way enough times!

[special-K]

Do you have that ad on TV out there where the boyfriend says "I'm never getting married" to his girlfriend, then they get married and he says "we're never having a baby" and they have a baby, then he says
we're not having another" and she tells him she's pregnant, then never a min-van and so on? I'm a stubborn hard head but I'm learning to use "never" very carefully. In fact, I should wipe it out of my vocabulary after all the nevers I have done. Ya never know (well, not usually)

[mongocanfly]

When I did my ls/nv4500 swap the tech at advance adapters told me to make the clutch fork slightly contact the pressure plate fingers, then adjust the fork back 1/4" measured at the tip on the pushrod end of the fork "to pull the throwout bearing off the pressure plate"..only takes about 1/2" to 5/8" of travel to release clutch..at that point the fork is slightly angled to the back..he never made any mention of any certain angle..but released it is slightly forward as shown in your picture.

[crazy longhorn]

Ideally....depress the clutch....(/.038-.050 Clearance, tween the clutch, & the hat, or flywheel (depressed). That 1/4" space will get you damn close, as Mongo said...longhorn Im never gonna do that....promise , that I wont break a trans.....O ya, I will never stop! Longhorn

[hdff]

Originally Posted by davepl

It's not my blue truck, it's a blue... car. I'm replacing a ZZ502 BBC with an LS3 eRod. But I prefer these forums over the Camaro forums so as long as the question is completely general to the LS motor, I ask here. If it's got anything to do with the car side, I ask there. Hope nobody minds so long as it's powertrain-only stuff.

So the big blue truck stays a factory big block. In fact this is the first time in my life I've ever replaced a big block with a small block, and heaven knows I've gone the other way enough times!

well it's good to know you go both ways...

[davepl]

So I gave up on the dead-reckoning, measure-from-both-directions method and skipped ahead to the final check.

I appear to have about -8 degrees of clutch angle (I put a protractor on a printout of the picture below), which is what is spec'd.

Is that all I have to do, or could I have this "correct" angle and still be messed up or incorrect with the pivot ball depth?

Thanks,
Dave